Apple confirmed the purchase Thursday without giving terms or describing its plans for the San Diego, California-based company. Emotient has tailored its facial-recognition software to advertising, media testing, audience response and research and other areas, according to its website.

Artificial intelligence has become a strategically important area for Apple as it seeks to build smart software tying together its numerous products. The world’s most valuable company has sought to hire more people to conduct advanced research in the field and acquired two other AI startups - Perceptio and VocalIQ - in recent months.

The ability to read emotions via a computer opens up a whole swathe of product areas, ranging from applications that change according to the perceived mood of the person to tools for studying how media affect a person’s state of mind. Emotient, founded by six researchers from the University of California at San Diego, had been granted patents covering areas such as the use of AI to read images and decipher whether a person would be attractive to another person. Another patent includes systems for gauging the tone of a conversation and automatically suggesting what can be said to improve the rapport of it.

Promising Technology

The Emotient deal, reported earlier by the Wall Street Journal, fits with Apple’s strategy of acquiring smaller companies with promising technology that can be integrated into future devices. Past acquisitions have influenced elements of current products such as the Siri digital assistant, iTunes, the semiconductors inside the iPhone and iPad and the search capabilities of its map service.

Other large technology companies have been exploring emotion-recognition technology. Microsoft has conducted research through its Project Oxford cloud service and IBM is developing products that can guess how a person is feeling from the tone of their voice.

London-based Realeyesand Waltham, Massachusetts-based Affectiva are among the startups with Emotient using artificial intelligence techniques to infer emotions from facial recognition software. Prior to the acquisition, Emotient also offered an off-line version of its product that could work without sending information back to a large data center. That lines up with Apple’s own artificial-intelligence work, which has explored designing services that preserve user privacy by not sharing data into the cloud. Perceptio had developed similar off-line capabilities.